Experts said that encouraging the sale of insurance across state lines could lower premiums some by weakening regulation, but that it would not have dramatic effects.

“It’s a fine idea, but it’s not a game-changer, to be honest,” said Douglas Holtz-Eakin, a longtime Republican policy adviser and president of the American Action Forum.

“Would it produce a little more competition in insurance markets? Probably,” he added.

The flip side, though, is that it would tend to reduce regulation of health insurance.

“Insurers would flock to the states that have minimal regulation,” said Larry Levitt, vice president of the Kaiser Family Foundation, which does nonpartisan health analysis.

While selling across state lines could have effects on the cost of health insurance, it would not do much to increase the number of people with coverage, experts said.

Holtz-Eakin said the cheaper coverage could to some extent help more people get insurance, but “not very much.”

Trump’s focus on allowing insurance to be sold across state lines is not satisfying experts.

“Selling insurance nationwide may be modestly helpful,” James Capretta, a healthcare expert at the conservative American Enterprise Institute, wrote in a blog post. “It does not come close to constituting a plan for fixing health care in the United States.”

Health savings accounts

At a CNN town hall earlier this month, Trump also pointed to health savings accounts as part of his plan.

Health savings accounts (HSAs) provide a tax-preferenced place for funds that people can spend on their healthcare. Paired with a high-deductible insurance plan, the idea is that HSAs help reduce healthcare spending by making patients more conscious of how they spend their dollars.

Health Savings Accounts already exist, but a proposal could look to ease rules that limit them.

ObamaCare’s insurance mandate

Trump has come under fire for embracing ObamaCare’s mandate that everyone have health insurance at the CNN town hall this month, saying “I like the mandate.”

He later walked back the comment, saying that he meant to say he favors keeping ObamaCare’s ban on insurers discriminating against people with preexisting health conditions.

ObamaCare pairs the ban on discrimination based on pre-existing conditions with the mandate for everyone to have coverage. The ban without the mandate is widely seen as a situation that would cause premiums to spike because people would wait until they are sick to get insurance.

Asked at the debate Thursday about insurance companies that make that argument, Trump replied, “I think they’re wrong 100 percent.”

A common Republican alternative to the mandate is to set up separate “high-risk pools” where people with pre-existing conditions can get coverage. Premiums would be higher than normal, so the government would subsidize people’s coverage.

The issue is that it requires government spending.

“Protecting people with preexisting conditions is probably the biggest challenge Republicans will face in crafting an [Affordable Care Act] replacement,” Levitt said. “It’s very hard to guarantee coverage to people with pre-existing conditions without regulations like the individual mandate or lots of government money to subsidize the market.”

Single-payer

Trump has also came under attack for his past praise for single-payer healthcare, which is anathema to Republicans.

“It works in Canada,” Trump said at the first Republican debate, in August. “It works incredibly well in Scotland. It could have worked in a different age.”

Trump said this month, though that his idea is “not single-payer.”

Trump has also pledged that he will “take care of people,” and at Thursday’s debate he repeated that he “will not let people die on the streets.”

Other critics don’t understand how Trump would take care of all of the sick.

“You have to say then, well, what exactly do you mean by that?” said Capretta, the American Enterprise Institute expert, adding that Trump has not offered “a single thing” that would show how he is going to take care of people.